Draft-regulator for furnaces.



A. M. SMITH. DRAFT REGULATOR FOR FURNACES.

APPLlCATION FILED NOV. 27. 1916..

1,245,282. v Patented Nov. ,1917.

2 SHEETS-SHEET I.

A. M. SMITH.

DRAFT REGULATOR FOR FURNACES. APPLICATION FILED NOV-27.1916.

1,245,282. v Pate med NOV. 6, 1917.

UNITED STATES PATENT OFFICE.

ALLEN M. SMITH, 0F FORT WILLIAM MGKINLEY, PHILIPPINE ISLANDS.

DRAFT-REGULATOR FOR FURNACES.

To all whom it may concern:

Be it known that I, ALLEN M. SMITH, a citizen of the United States,residing at Fort William McKinley, Philippine Islands, have inventedcertainnew and useful 1mprovements in Draft-Regulators for Furnaces; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which-it appertains to make and use the same.

This invention relates to improvements in automatic damper regulatorsfor furnaces.

One object of the present invention is to provide a device wherebyopening or closing of the damper w'll take place, only, at apredetermined time.

Another object is to provide a device of this character wherein theoperation of o ening and closing the damper will continue to take placeas the temperature rises and falls, after the time mechanism has beenbrought into play.

Another object is to provide a device of this character wherein novelmeans hold the parts of the damper actuating mechanism in one directionof its movement until automatically shifted by a change in temperature.

Other objects and advantages will be apparent from the following takenin connection with the accompanying drawing.v

In the drawing:

Figure 1 is an-elevation of my regulating device in connection with afurnace,

Fig. 2 is an enlarged elevation of the thermostat,

Fig. 3 is an enlarged elevation of the thermostat with the clockremoved,

Fig. 4is an enlarged vertical sectional view on the line H of Fig. 2,

Fig. 5 is an enlarged vertical sectional view on the line 55 of Fig. 1,

Fig. 6 is a rear elevation of the clock,

Fig. 7 is a diagrammatic view of the wiring of the device.

Referring particularly to the accompanying drawing, 10 represents avertically disposed casing in which is arranged a vertical thermostaticbar 11 Secured to and extending through the lower end of the bar is apin 12, the ends of which are provided with sharpened portions 12', forengagement in the hollow ends of the contact Specification of LettersPatent.

description when- Patented Nov. 6, 1917.

Application filed November 27, .1916. Serial No. 133,645.

screws 13 carried by the opposite sides of the lower end of the casing.These screws are provided with the heads 14, externally of the casingfor purpose of adjustment thereof. Mounted on the front of the easing,and closing the same, is a removable plate 15, carrying a thermometertube 16.

Carried by the lower end of the casing is a wooden or other insulatedbase 17, through which extends a pin 18, said pin being rigidly held fora purpose which will be later set forth. Mounted on the outer face ofthe base is a bracket 19, through which is formed an opening 20 for theslidable reception of a plunger 21. In the base 17 beneath the bracket,.is an opening in which is secured one end of a conductor wire 22. Thiswire is held in place by the binding screw 23, which in turn holds aninsulated washer 2% on the outer face of the base. Un the plunger,inwardly of the bracket, is a transversely extending pin 35, againstwhich bears one end of a coil spring 26. This spring encircles theplunger, and bears with its other end against the face of the base 17,the insulated washer 2% being received in this end of the spring to holdthe same from lateral movement tending toward contact with the screw 23.Connecting the screws 13 and 23 is the beforementioned conductor wire22. Connected to the pin 18, at the rear of the base 17, is anotherconductor wire 27, which will be more fully explained later. At twodiametrically opposite points on the outer face of the base 17 are themetallic plates, each of which is formed with a keyhole slot 28. for thereception of the screws carried by the back of the clock 29.

From an inspection of the drawing, it will be seen that when the clockis placed in its proper position on the base 17, the metal casingthereof will force the plunger 21 inwardly, against the tension of thespring 26, so that the inner end of said plunger will Contact with screw23, to which the wire 22 is attached. The clock is of the ordinary alarmtype, and includes the winding stem 30, for the alarm mechanism thereof.

Mounted above the furnace 31, at a suitable point, is a pair of casingsor housings 32, supported by a connecting bar or beam 33. 1n each ofthese casings or housings are arranged the electromagnets 34: and 34/each set of which is provided with the armature 35, carried by one endof the centrally pivis equipped with a weight 39. mounted within eachhousing,

oted lever 36, which l ver is mounted in :1 depending bracket 37 carriedby the beam 33, between the housings. The ends of the bar extend throughthe housings, as clearly shown, the one projecting end being connectedto the draft door 38 'of the furnace by means of a chain 38, while theother end Pivotally over the end of the bar or lever 36, is a weightedarm 40 which is adapted to fall on the said end of the lever to preventrebound thereof when drawn downwardly by the electromagnets. Thisweighted arm is, however, only heavy enough to hold the lever fromrebound, but on the other hand can be easily and quickly raised by thelever when the opposite end is drawn down by the other set of magnets.The sets of magnets are connected by a conductor 41, a common returnwire 42 leading therefrom to a set of batteries, or other source ofelectricity. The batteries are represented at 43, from the other side ofwhich extends a conductor 44, said conductor being connected with thethermostatic bar 11.

The connections to the electromagnets are properly led through circuitbreakers or switches, each including the jaw 46, which is connected tothe adjacent magnet by the wire 46, and the pivoted gravity arm 47, oneof said arms being connected to the contact screw 13 by the wire 45, andthe other to the pin 18 by the wire 27, so that when the lever 36 rocksin either direction on its pivot, it will engage with one of the armsand swing the arm out of contact with the jaw 46 and thus break thecircuit from the magnets last energized. It will be readily understoodthat when the said lever rocks in one direction it raises the draft doorof the furnace, through the chain, While when it rocks in the oppositedirection it permits the door to fall into closed position, by gravity.

If desired, I may provide the wiring with a common screw connection plugso that the ordinary electric lighting circuit may be used. This is, ofcourse, optional and is thought to need no illustration.

It will be understood, from the foregoing, that when the temperaturerises above a predetermined point, the thermostatic bar will bend towardthe contact screw 13, so as to contact therewith. This completes acircuit through the left hand set of electromagnets, of Fig. 1, anddraws the adjacent end of the lever 36 down, with the result that thedraft door will be permitted to fall into closed position. If, however,the temperature falls below the predetermined point, nothing will takeplace, except that the thermostatic bar will bend into contact with theother screw 13, for the reason that there is no connection between theclock casing and the pin 18. When, however, the alarm of the clock goesoff at the predetermined time, the winding stem thereof will turn untilit contacts with said pin 18, thus completing the circuit through theother set of electromagnets and causing the rocking of the level 36 inthe other direction, with the result that the draft door will be liftedinto open position and the fire allowed to burn up. It will beunderstood that when the alarm mechanism is wound up, the finger pieceof the stem is left in a vertical position so that it will not touch thepin '18.

Attention is particularly called to the peculiar arrangement of thealarm winding stem and the contact pin 18, which automatically controlsthe closing of the circuit. This is particularly adapted for use atnight, the alarm being set to go off at, say six oclock, whereupon thewinding stem will turn into contact with the pin 18. During the nightthe temperature falls considerably below the normal, but it is notdesirable to have the draft door opened in the middle of the night andthe fire Jermitted to burn up and possibly result in res or in burningout. Therefore, no matter how far below the normal the temperature mayfall, during the night, the draft door will not be actuated until thealarm goes off and completes the circuit through the pin 18.

What is claimed is:

A draft regulator for a furnace includin electrically operated draftdoor means, an a circuit controlling device consisting of a supportincluding an insulated base, a thermostatic bar mounted on the support,contacts carried by the support for engagement by said bar, a. pair ofmetallic brackets mounted 'On'the base and formed with keyhole slots, astationary contact element carried by the base, a resiliently supportedme' tallic pin mounted for movement toward 1 and away from the contactelement, a rigidly mounted metallic pin base, a metallic clock havingheaded-members engaging detachably in the keyhole slots and in metalliccontact with the said brackets and with the resiliently supported pin,whereby said pin is forced into contact with the stationary element, awinding alarm stem carried by the clock for engagement with the rigidpin, and a source of electricity including the said contacts and thedoor means in the circuit thereof.

In testimony whereof, I aflix my signature, in the presence of twoWitnesses.

ALLEN M. SMITH.

also carried by the Witnesses:

CHAS. C. BILLINGHAM, OT'ro A. TANDROP.

